JP3867454B2 - Membrane separation and purification equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a membrane separation device for the purpose of water purification, solid-liquid separation, and the like, and more particularly to a membrane separation and purification device capable of preventing clogging of membranes by living organisms and contaminated organic substances.
[0002]
[Prior art]
For the purpose of solid-liquid separation and the like, there is a purification device that separates and removes particles with a thin water membrane or a membrane knitted with polymer fibers as a water separation membrane. Examples thereof include those described in the chemical technical journal MOL Vol.22, No.12 p47-51, (1984).
[0003]
A membrane is formed of stainless steel fine wire, copper fine wire, polyester fiber, or the like, and the water to be treated passes through an opening having an opening of, for example, several tens of micrometers. Objects to be treated in the treated water, such as phytoplankton such as blue sea bream, animal frankton, organic matter, and other contaminants cannot be passed and captured and separated if the projected area or projected diameter is larger than the projected area or projected diameter of the opening. The water that has passed through the membrane becomes purified water. If the water to be treated continues to flow through the same membrane surface, the material to be treated accumulates on the water flow side surface of the membrane, the water flow resistance increases, the water flow rate decreases extremely, and the purification operation is hindered. . Therefore, the film surface with the deposit in the portion below the surface of the water to be treated is moved to the atmosphere above the surface of the water to be treated, and the film is washed using, for example, shower-like purified water. The mixed water of the cleaning water and the sediment is removed from the separation unit system as sludge, and the membrane surface is cleaned and regenerated and returned to the portion below the liquid surface to be treated. A small amount of phytoplankton, zooplankton, zooplankton, tiny animal larvae and eggs, organic matter, etc. that could not be washed with shower water remain on the surface of the membrane.
[0004]
Ultimately, the sludge is usually transported to a disposal site or incinerator by a truck or composted.
[0005]
[Problems to be solved by the invention]
As described above, in the conventional example, a small amount of phytoplankton such as aquatic, zooplankton, minute animal larvae and eggs, organic matter, etc. that could not be washed with shower water remained on the surface of the membrane. When organisms propagate and stick to the membrane, they cannot be removed with shower water, and the membrane is clogged or narrowed to reduce the amount of water flow, thus degrading the purification performance.
[0006]
An object of the present invention is to obtain a membrane separation and purification device that can prevent clogging of membranes caused by organisms and polluted organic substances.
[0007]
[Means for Solving the Problems]
The object includes the object to be removed and the seeding material by adding a seeding material and a flocculant having a higher density than the object to be removed to the fluid to be treated or the fluid containing the object to be removed. A means for generating flocs, a fluid to be treated in which the flocs are generated is filtered, and a filtering means comprising a mesh having an opening through which an object to be removed or floc cannot pass, and captured on the surface of the filtering means The membrane separation purification provided with cleaning means for moving the deposits such as the removal object and flocks above the liquid level of the fluid to be treated and separating the deposits from the surface of the filtering means by a hydrodynamic force In the apparatus, this is achieved by providing ultraviolet light that irradiates and sterilizes the inner and outer surfaces of the filtering surface of the filtering means.
[0008]
Here, it is further preferable that the filtering means is constituted by a fine mesh wire, and the photocatalyst is immobilized on the surface of the fine mesh wire.
[0009]
That is, in the present invention, for example, after the film is washed using shower-like purified water, an ultraviolet ray generating lamp that irradiates the film surface with ultraviolet rays is disposed. In addition, titanium oxide particles or a film is coated on the surface of a stainless steel fine wire or a copper fine wire, and the surface is irradiated with ultraviolet rays to generate active oxygen on the surface.
[0010]
Due to this germicidal action by UV irradiation, a small amount of phytoplankton such as sea cucumbers, animal flanks, larvae and eggs of minute animals that could not be washed with shower water will die and will not proliferate and remain with active oxygen. It is oxidatively decomposed with contaminated organic matter and then washed with shower water. Therefore, there is obtained a membrane separation and purification device capable of maintaining the purification performance over a long period of time without clogging or narrowing the membrane and reducing the amount of water flow.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below with reference to FIGS. 2 is an enlarged cross-sectional view of the membrane separation and purification device 8 of FIG. 1, and FIG. 3 is a half cross-sectional view as seen from the top of FIG. Raw water, which is to be treated, is pumped from a water source, for example, a reservoir 1 to a raw water storage tank 5 by a pump 4 through a conduit 2 and a filter 3 for removing large garbage, and this raw water 6 flows into a membrane separation and purification device 8 through a pipe 7. .
[0012]
The structure of the membrane separation and purification device will be described with reference to FIGS. A film 9 having an opening having an opening of several to several tens of micrometers made of stainless steel fine wire, copper fine wire, polyester fiber or the like is formed in a drum shape, and both ends of the film 9 are drums having no openings. Are joined to the flange 12 in one direction, and the flange 12 is joined to and integrated with the rod 12, and the center of the flange 12 is joined to the rod 13 and the rod 13 is rotated by the motor 14. 10. Drum-like film 9 and shell 11 rotate. The shell 11 and the fixed flange 15 are slidably rotated while maintaining airtightness on the sliding surface 16. A purified water tank 17 is disposed outside the membrane 9. The raw water 6 flows from the conduit 7 into the drum-shaped membrane 9, and the raw water 6 passes through the membrane 9. At this time, the object to be removed 18 in the raw water 6 is captured by the inner surface of the membrane 9, and the water that has passed through the membrane 9 and separated from the object to be removed 18 becomes purified water 19 and accumulates in the purified water tank 17 and passes through the pipe 20. Released into reservoir 1. The power that the raw water 6 passes through the membrane 9 is the liquid level difference between the raw water 6 and the purified water 19. On the other hand, the object 18 to be removed adheres to the inner surface of the film 9 rotating counterclockwise in FIG.
[0013]
The exposed deposit 18 to be removed does not immediately impede water flow. However, when the deposit increases after a long period of operation, it impedes water flow. Purified water in the purified water tank 17 is sucked from the water intake port 22 of the pump 21 and sent from the conduit 23 to the shower tube 24, and shower water 25 is blown from the hole to the inner surface side from the outer surface of the membrane 9. Deposits accumulated on the inner surface of the film 9 are peeled off by shower water, the surface of the film 9 is regenerated, and cleaning water containing the deposits accumulates in a tray 26 provided inside. The washing water flows away from the drain port 27 and accumulates in the sludge tank 29 through the pipe 28.
[0014]
There is a possibility that microorganisms or the like in the raw water adhere to and propagate on the inner and outer surfaces of the washed membrane 9 and block the eyes of the membrane 9. In order to prevent this, in this embodiment, the ultraviolet lamps 30 and 31 are inserted into the protective glass tubes 32 and 33 and arranged. On the inner surfaces of the protective glass tubes 32 and 33, an aluminum vapor deposition film is attached to the upper half and the lower half, respectively, so that the ultraviolet rays are reflected and the inner and outer surfaces of the film 9 are irradiated with the ultraviolet rays. Eggs and larvae of animal and phytoplankton organisms attached to the membrane 9 do not propagate on the net by being killed by ultraviolet rays, and the membrane 9 is closed or narrowed to impair the purification function. Can be prevented. Further, by immobilizing an active oxidation catalyst material such as titanium oxide on the fine wires and fibers constituting the membrane 9, active oxygen can be generated by irradiation with ultraviolet rays. With this active oxygen, organic matter adhering to the film 9 can be oxidatively decomposed to remove dirt such as organic matter on the film 9.
[0015]
The sludge accumulated in the sludge tank 29 is concentrated by a dehydration facility 35 such as a centrifuge or a belt press through a pipe 34 and then processed into compost or the like.
[0016]
In this embodiment, the case where the film 9 is formed in a drum shape has been described. However, even if the film 9 is configured in a disk shape and a plurality of the disks are arranged in the vertical direction to configure the purification device, A similar membrane separation and purification device can be obtained by irradiating the inner and outer surfaces with ultraviolet rays.
[0017]
FIG. 4 shows another embodiment of the present invention. The difference from the embodiment of FIG. 1 is that the raw water 6 is provided with a seeding addition device 36 and a pipe 37 for adding a seed material of sand particles such as minerals having a high density or crushed glass particles. a pH adjusting agent, a chemical addition device 38 for adding a flocculant such as polyaluminum chloride and a polymer reinforcing agent, and a pipe 39; a stirring tank 40 for stirring the raw water and these additives; The motor 41 that rotationally drives the stirring blade 42 is provided. As a result, the pretreated water 43 containing a large amount of flocs having a large density is generated, which includes the object to be removed and the seeding material having a size of several hundred microns to several millimeters. The pretreated water 43 is passed through the conduit 7 to the membrane separation and purification device 8.
[0018]
The point that the floc separated by the membrane 9 is washed with the shower water 25 and the washing water containing the floc is collected by the tray 26 is the same as the embodiment described with reference to FIGS. 2 and 3, but in this embodiment, Compared to the case where the object to be removed having a low density is washed, since the volume and density of the floc are large, the gravity and shower water are stored on the floc surface during washing, and the gravity acts to reduce the amount of shower water. It can be easily peeled off from the membrane 9 and sludge can be recovered. Therefore, in this embodiment, a highly concentrated sludge having a small moisture content in the sludge can be obtained. Therefore, the processing capacity of the dewatering means such as the centrifuge at the rear stage is small, and there is an effect that the apparatus cost and the operation cost can be reduced. Further, in this embodiment, shower water is used for peeling flocs from the membrane 9, but the density is high even if compressed air is emitted from the shower tube 24 as a high-pressure air shower by an air compressor instead of shower water. The floc is easily peeled off and the membrane 9 can be cleaned. In this case, since water is not used for washing, the moisture content of the flocs peeled off can be further reduced to obtain highly concentrated sludge. Therefore, it is possible to reduce the processing capacity of the dehydrating means such as the centrifuge on the rear stage side, and to reduce the apparatus cost and the operating cost.
[0019]
The recovered sludge is pyrolyzed, and the sludge is sent to the downstream side from the sludge tank 29 via the pipe 44 and the slurry pressurizing pump 45 in order to reduce the sludge volume and recover and reuse the seeding material. At the inlet of the slurry pressurizing pump 45, water necessary for processing with high-temperature and high-pressure water, an alkali solution of a reaction accelerator and a neutralizing agent, etc. are added to the sludge through the valve 47 from the chemical tank 46.
[0020]
The sludge pressurized to about 2 MPa by the slurry pressurizing pump 45 is discharged into the reaction tube 48, preheated by the preheating heat exchanger 49 for heat recovery after the treatment, and by the temperature controller 50 incorporating a heater or the like. The temperature is brought to a subcritical state of 200 degrees.
[0021]
Here, plants, zooplankton, and the like, which are objects to be removed in the sludge, are organic substances, and there are inorganic and organic flocculants. Therefore, the aggregates of flocs and aggregates in subcritical water are broken, the solids in the flocs fall apart, and the organic matter becomes a subcritical solution with a mixture of oily viscous liquid and moisture, and seeding in sludge The flocculant is peeled off around the material and separated by the seeding material alone. Accordingly, in the seeding material separator 51, a high density seeding material settles from the side wall side and accumulates in the lower part due to a cyclone action by a rotating flow. When the seeding material accumulates to some extent, the valve 52 is opened and the seeding material slurry is recovered in the recovery tank 53 using the internal pressure. The recovered seeding material is reused.
[0022]
After the sludge exits the seeding material separator 51, the oxygen, hydrogen peroxide solution, air, eutectic reagent, alkaline solution, etc. necessary for the oxidation treatment in the high-temperature high-pressure water are supplied from the chemical tank 54 to the valve. Through 55, it is added to the sludge in the reaction tube 56 with a built-in heater. The sludge whose temperature is controlled in the reaction tube 56 is oxidized in the reaction tube 56 to reduce the volume of organic substances contained in the sludge, and the phosphorus present in the sludge is converted into phosphate by a chemical reaction to form a solid precipitate. Become. A safety valve 57 is attached to the line of the reaction tube 56.
[0023]
Thereafter, the high-temperature and high-pressure sludge solution passes through the pipe 58, recovers heat by the preheating heat exchanger 49, and is depressurized and sprayed from the flash tank 59 through the pressure regulating valve 60. The inside of the flash tank 59 is adjusted to a pressure slightly higher than the atmospheric pressure by the pressure adjusting valve 60. Here, a part of the water in the high-temperature / high-pressure sludge solution is self-evaporated by the internal heat capacity, and the rest is heated and evaporated by a built-in heater or the like, and the evaporated vapor keeps the flash tank warm, and from the pressure regulating valve 61 Released. In the flash tank 59, the unoxidized organic matter and inorganic molecules in the sludge are dried and solidified, and the dried matter is settled and separated at the bottom of the container and taken out of the tank. The solution is introduced via the pipe 62 and the flow rate adjusting valve 63. The raw water is mixed with the pipe 64 and the water quality is adjusted, and then discharged into sewage and vegetation facilities.
[0024]
In this example, the flocculating action of the flocculant is broken in high-temperature and high-pressure water, the solid matter in the floc is broken, the flocculant is peeled off from around the seeding material in the sludge, and can be separated by the seeding material alone. When used, a high-purity seeding material can be recovered. Since sludge can be processed without using a concentrating means such as a centrifugal separator or a belt press machine, the apparatus cost can be reduced, and the sludge volume can be reduced, so that the sludge treatment cost can also be reduced.
[0025]
In this embodiment, the present invention can also be applied to a case where a mixture of a seeding material and a material to be removed is not separated without using a flocculant and without generating a floc containing the material to be removed. Can be reused.
[0026]
In addition, a seeding material of approximately the same size as the object to be removed or smaller than the object to be removed and captured by the membrane is poured into the raw water and mixed, and the object to be removed is mixed with the seeding material on the membrane surface. The same effect can be produced without using an aggregating agent by trapping and depositing the mixture having a high density so as to be peeled off from the film by the water pressure and gravity of the shower water with a small amount of shower water.
[0027]
In the present embodiment, an ultraviolet lamp is used as the sterilizing means, but the same effect can be obtained by sterilization treatment by electromagnetic wave irradiation or electrical conduction.
[0028]
Further, in order to clean dirt on the outer surfaces of the protective glass tubes 32 and 33, purified water is used as cleaning water, and the outer surface is mechanically brushed or wiped or continuously or periodically with cleaning water. If cleaning means for peeling off and removing dirt is provided, the sterilization efficiency of ultraviolet rays can be maintained. In this case, a mechanical brush, a wiper, and a washing water blowing hole may be fixed, and the entire circumference of the outer surface may be washed while rotating the protective glass tubes 32 and 33 during washing.
[0029]
【The invention's effect】
According to the present invention, since sterilizing means such as ultraviolet irradiation is provided, the sterilizing action kills a small amount of phytoplankton such as sea cucumber, zooplankton and tiny animal larvae and eggs that were not washed and partitioned with shower water. Since the growth can be prevented, it can be oxidatively decomposed together with the remaining polluted organic matter with active oxygen and then washed away with shower water or the like. Therefore, there is an effect that it is possible to prevent the membrane from being clogged or the eyes from becoming narrow and to reduce the amount of water flow, and to obtain a membrane separation and purification device capable of maintaining the purification performance for a long period of time.
[Brief description of the drawings]
FIG. 1 is a system diagram of a membrane separation and purification device showing an embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of the membrane separation and purification device shown in FIG.
3 is a plan view showing a partial cross section of the membrane separation and purification device of FIG. 2; FIG.
FIG. 4 is a system diagram of a membrane separation and purification device showing another embodiment of the present invention.
[Explanation of symbols]
6 ... Raw water, 9 ... Membrane, 17 ... Purified water tank, 18 ... Objects to be removed, 19 ... Purified water, 25 ... Shower water, 30, 31 ... UV lamp, 32, 33 ... Protective glass tube.

Claims (2)

A floc containing the to-be-removed object and the seeding material is generated by adding a seeding material and a flocculant having a density higher than that of the to-be-removed object to the fluid to be treated or the fluid containing the to-be-removed object. Means for filtering the fluid to be processed in which the flocs are generated, the filtering means comprising a mesh having an opening through which the object to be removed and the floc cannot pass, and the removal target captured on the surface of the filtering means In a membrane separation and purification apparatus comprising a cleaning means for moving deposits such as deposits and flocks above the liquid level of the fluid to be treated, and separating the deposits from the surface of the filtering means by water flow force ,
An apparatus for separating and purifying membranes, characterized in that ultraviolet rays that sterilize by irradiating the inner and outer surfaces of the filtration surface of the filtration means are provided . The membrane separation and purification device according to claim 1,
The membrane separation and purification device , wherein the cleaning means comprises a pump that sucks up the purified water purified by the filtering means and a shower tube .

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